The present invention concerns a method for the radial compression of cylindrical bodies composed of comlpressible material, in particular of rolls composed of wound flat structures, especially those which re-expand after removal of the pressure and therefore return to the original condition.
Cylindrical bodies such as are obtained by rolling strip material composed of loose, air-containing materials such as tufted textiles, fleeces, crepe, foamed material strips and the like, are voluminous and involve a large storage and transport volume, which has a substantial adverse effect on storage and transport costs.
Although it would be quite possible to compress such cylindrical bodies in the radial direction and hence economize on storage and transport volumes, no method which is usable in practice has previously been available for the solution of this problem. Winding such strips using a strong tensile stress, for example, which should lead to a reduction in volume, is not possible, either because the products lack the necessary tearing strength or else, particularly where knitted or non-woven tufted flat textile structures are concerned, they would be stretched by the tension and their structure changed.
Attempts to achieve radial compression by making the cylindrical body pass through a circular opening of smaller diameter than that of the cross-section of the cylindrical body fail because of the strong surface friction which not only demands a substantial expenditure of force but also, due to the surface friction, leads to surface damage.